Figure 2.

Side-by-side comparison of structures of HiDapE in two different conformations. (A) Ribbon diagram of the previously reported holoenzyme structure of HiDapE in its “open” conformation (PDB entry 3IC1). (B) Structure of the complex of HiDapE with the products succinic acid (magenta) and l-diaminopimelic acid (yellow), in the closed conformation. Individual subunits of the homodimer are colored green and orange. Panels C and D show the complexity of the domain movements for HiDapE. (C) Extent of rotational conformational changes as observed by superimposition of the catalytic domains of the monomers of open (gray) and closed (orange) structures. (D) Movement within the dimerization and catalytic domains as revealed by superimposition of the dimerization domains of the open and closed conformation structures.